Thread: Should properly seasoned timber cup after dressing?

Did supplier ever mention the moisture content to you?If not,check yourself, with a quality moisture meter(try to borrow one as they are very expensive).Not sure what % of moisture is acceptable for Jarrah,sold as seasoned,but i'm guessing between 8-14%,

As said above, make sure you use a good quality meter not one of cheap ones

Sometimes after thicknessing etc the stresses change and away it goes or just a change in humidity. Once I have boards glued together I always clamp them down to either the job or my bench top to keep them flat untill I casn get some finish on them. Once the finish is on then they should settle down but I would still keep them clamped. I don't usually make a top untill I can fix it to the piece. And be carefull how you fix it. Make sure you use slotted holes or table top clips etc.
Moisture content will also vary depending on ambient relative humidity.

dc
I'm not surprised with your experience
the humidity has been all over the place over the past 2 weeks
also, you haven't said how the grain is arranged in the boards you glued together

My guess is its all backsawn material and it aint seasoned. As a guide for you guys over in the east, south of Sydney the moisture content should be around 12% to be safe. Above that 10% is good. The higher in humidity*( not season change) that jarrah is in, the more likely it is to move

Boards probably should have been sealed straight after sanding.Timber will release moisture,and absorb it.One week they might be at 8% e.m.c,the next at 12%.Certainly backsawn boards are difficult to stabilize,but riftsawn boards can move also.Always a good rule of thumb to purchase quartersawn boards where possible,but make sure they are seasoned also.

I'm not familiar with Australian woods but all woods are similar in some respects.
The key word in your question is "should". Wood does not always obey orders very well. No, it shouldn't. But it often does what it wants regardless of what precautions you take. Yes, it can and sometimes it will cup even years after your project was completed. That is part of the joy of being a woodworker/turner.

Gun stocks for the top grade guns are cut from trees two or three hundred years old, and the blank is left for another 25 years. So if that is the time frame for completely seasoned timber what chance do we have.
les

And.... unless your garage is kept at exactly the same temperature and humidity as your house, more movement can be expected once the piece of furniture gets indoors. Usually this is controlled by the methods of construction but there are no guarantees.
Cheers,
Jim